Manufacture of blanks of sheet metal



F. DRURY.

MANUFACTURE OF BLANKS 0F SHEET METAL.

APPLICATION FILED SEPT. l I. 1920.

Patented July 25, 1922.

2 SHEETS- SHEET 1.

' fizwn F. DRURY. MANUFACTURE OF BLAN'KS 0F sum METAL.

APPLICATION FILED SEPT. I Ir 19 20- i 1 ,424 O05. Patented July 25, 1922.

2 SHEETS-SHEET 2.

I UNITED STATE S PATENT OFFICE} FRANK DQEURY, 0F AIN TREE, LIVERPOOL, ENGLAND,-'ASSIGNOR T0 G. H. WILLIAMSON & SONS, LIMITED, OF WORCESTER,

ENGLAND, A CORPORATION OF GREAT BRITAIN,

MANUFACTURE OF BLANKS 0F SHEET METAL. 4

To all whom it may concern Be it known that I, FRANK DRURY, subject of the King of Great Britain, residingat No. 8 Barnslow Road, Aintree, Liverpool, England, I I useful Improvements in or Relating to the Manufacture of Bl'anks'of Sheet Metal, of which the following is a specification.

This invention relates to the manufacture of sheet metal blanks suitable for use as the ends of cylindrical boxes and boxes of a shape in cross section other than rectangular and for purposes generallyfor'which sheet metal blanks of a shape other than rectangular are or may be required and the said invention consists of the improvements hereinafter described in the production of the strip metal from which such blanks are pressed or punched in ordinary blank forming machinery, the said improvementshaving for their principal objects to simplify the production of the metallic strips with regular zig-zag or undulating edges and to effect the maximum economy of metal in the production of the said metallic blanks or in other words to simplify and" reduce the cost of manufacture of metallic blanks.

In order that my invention may be the better understood I remarkthat in certain blank forming machinery at present in use the blanks are or may be pressed or punched from a strip of sheet metal having in its opposite longitudinal edges a series of waves or serrations, such shaped metallic" strips be ing used in order to economize material.

y invention consists of the improved method hereinafter described of obtaining such strips from sheet metal and in carrying the invention into effect Iemploy shearing tools or blades having in plan a serrated or waved form on their cutting edges the sheet being fed forward after each cutting operation which extends from edge to edge or side to side of the sheet, a distance equal to the width of the strips to be obtained from the sheet minus the depth of the serrations at one side thereof and shifted alternately from right to left at each succeeding cutting operation to an extent equal to one half, or odd multiples of one half, of the pitch or wave length of th said serrations limiting guides or stops being provided on the bed of the shearing machine for determining the extent of the rearward and side-way motions Specification of Letters Patent. Application filed September 11 1920.

have invented certain new and Patented July 25, 1922. Serial No. 4o9,727.

the machine which tools or blades may be worked by hand or treadle or be power operat ed I I will further describe. my invention in connection with the accompanying drawings Figures 1 and 2 of which represent in plan portions of sheets operated onin the manner described to provide strips of the shape represented in the said figures one strip being shown in full lines in each figure the said strips being subsequently operated on in ordinary blank forming machines for the punching therefrom of blanks. I

Figure 3 represents a sheet similarly operated on to produce strips, one of which is shown in full lines, from which oval or e1 liptical blanks are to tained.

circular or polygonal Figure 4 represents in elevation and Fi an so much of the machine in which the plates are operated on for the production of strips as is necessary for the understanding of the invention, the cutting edges of the blades represented in thesaid figures having the shape, as is best seen in the plan view Figure 5, for producing ure 5 in pl strips of the contour represented in Figure 21' Figure 6 is across section through the rear part of the machine on the plane indicated by the dotted line 6-6 in Figure 4."

The same letters of reference indicate the same parts in the said Figures 4, 5 and 6.

a is the bed or table of the machine carr ing at its rear edge the lower shear tool or blade 6, and c is the upper tool or blade carried by the slide (Z working in the slotted guides e, e at the sides of the machine. a

To the rear of the bed and shear blades is arranged a bar f the ends of which are supported on slotted brackets g, g the said bar being capable of adjustment relatively to the blades and being secured in its adjusted position by screw bolts h, it passed through the ends of the bar and working in the slots of the brackets the said bolts being provided with clamping screw nuts 2', 2'.

On the upper side and at each end of the table is arranged a stop bar 71: which may be so attached to the table, for example by screw pins m, m, as to be readily removable and replaceable by bars of varying widths, or the said bars may be made capable of lateral adjustment on the bed or table for the purpose of so positioning the same therebe subsequently obon as to regulate with great nicety the extent tov which the sheet ismoved alternately from oneside to the other on the bed to bring the said plate into the requisite position relatively to the shear tools or blades b c.

v ln operating with the machine for producing the strips Figure 1 the bar or stop f is adjusted so that the distance marked on the plan Figure 5 is equal to thedistance marked :0. on the said strip Figure 1, that is to say, is equal to the maximum width or thestrip to. be produced. The side stops or guide barslc, is are taken of such a width, or are laterally adjusted on the bed so that the distance between their presented or acting inner edges exceeds the width of the sheet to be operatedon by one half the pitch or wave length of the serrations or undulations of the strip which distance is denoted by g at the right hand end of the said strips Figures 1, 2 and 3.

In the plan view Figure 5, the distance through which the-sheetis moved laterally is denoted by the line .2 between the right hand.

edge 8 s oi a sheet 8 indicated in dotted lines on the bed (5 the left hand edge of the said sheet 8 being coincident with the left.

hand stop or guide bar is.

I In making the first cut on the sheet the said sheet is not fed up to the stop bar f but is only fed sufficiently far between the shear tools or blades b, c to takeoff a strip (indicated by dotted lines along the upper edge of Figure 1) to produce the first serrated edge on the sheet. After the first cut the sheet is fed rearwardly until its cut or serrated edge comes againstthestop bar f and laterally until its right hand edge comes against the right hand stop or guide bar 7:: when the next shearing operation is eti'ectcd'. The lateral displacement of, the sheet is clearly indicated by the relative position of tne fullline and. dottedline side edges 8, s of the sheet in Figures 1 .2 and 3 the dotted lines indicating the said edges when the sheet has beenfmoved to the requisite distance to the right after making the cuttingoperation which produced the upper serrated edg of the strips shown in full lines and before making the cutting operation to produce the lower serrated edges of the said strips. Succeeding cutting operations are efiected on the sheet: by bringing the last out and serrzgtededge-up to the rear stop 7 and at each rearward movement shitting the said sheet laterally so as to bring its left and right hand sides or edges alternately against the left and right hand stops or guide bars 70, 70 respectively.

or instead of first cutting a narrow waste strip from the sheet to produce the first serrated,v zigzag or undulating longitudinal edge thereon av strip may be produced with a plain edge at one side and zig -zag or undulating edge at its other side the parts of the strip of maximum width being equal to the parts OfHHIXlDlUlH width in a strip having both edges zig-zag or undulating.

By the method and with blades having the cutting edges of suitable contour described sheets are divided with great accuracy into uniform strips with zigzag or undulating longitudinal edges and inasmuch as the counter parts of the projections on one edge oi" the severed strips are made to constitute the projections on one edge of the next strip to be severed the sheet is divided into the requisite strips with practically no Waste of the material. 7

The strips obtained are subsequently 0perated on in blank forming machines to pro duce circular, polygonal or oval or elliptical blanks as indicated in dotted lines on the strips shown in full lines in Figures 1, 2 and 3.

I claim 1- A shearing; machine for the production of sheet metal strips with zig-zag or waved longitudinal edges having in combination shearing tools the cuttingedges o't'which. are. the requisite zig-Zag or waved cont-our, an adjustable stop to limit the forward movement of said sheet metal and adjustable stops. to limit the sidewise movement of the sheet metal, said last mentioned stops being so set that the metal may be shifted 'li'or alternate cutting operation to right or leiit a distance equal to one-half the pitch of the zigaag or waved longitudinal edges.

In testimony whereof I have hereunto set my hand.

FRANK DRURY. 

